Swiss utility company EOS has said that its Cleuson-Dixence hydroelectric plant in Valais will continue to remain closed for several months until repairs to an underground penstock are completed. The penstock broke 100m underground and released about 50,000m3 of water, laden with mud and debris, into the valley of the river Rhone on 13 December 2000. About 9m of the pipe was damaged.
The 1200MW plant is one of three hydro power plants on Lake Dixence, the other two plants have a capacity of 800MW. EOS has a 72% stake in Cleuson-Dixence, a 60% stake in the 680MW Grande Dixence plant and is the sole owner of the 120MW Thandoline plant. Cleuson-Dixence was commissioned in 1998 and has been fully operational from the beginning of 1999. The three plants generate 1.85TWh of electricity a year.